JPH10510181A - Adjustable vertebral body replacement - Google Patents

Abstract

A vertebral replacement implant (20) for interposition in a space left by one or more removed vertebrae between adjacent intact vertebrae, comprising : a replacement body (21) with opposite ends sized to span a portion of the space between the intact vertebrae, said replacement body having first threads defined thereon at each of said opposite ends ; and a pair of endplates (22) each having an end surface (23) for contacting a respective one of the intact vertebrae when the implant is interposed in the space between the intact vertebrae, each of said endplates including a cylindrical portion having second threads defined thereon configured to threadedly engage said first threads on said replacement body; and characterized in that each of said endplates (22) includes a flange (35) defining said end surface (36) and extending outwardly from said cylindrical portion (37), said flange (35) including an arm (14) projecting away from said cylindrical portion (37), said arm (14) having a free end configured to extend beyond the adjacent intact vertebrae for engagement to a longitudinal member (105) disposed along the length of the spinal column.

Description

DETAILED DESCRIPTION OF THE INVENTION Adjustable Vertebral Body Replacement Background of the Invention The present invention relates to an implant for replacing one or more vertebral bodies and their adjacent discs. More specifically, the vertebral body replacement is particularly suitable for implantation through an anterior approach. The treatment of spinal injury has advanced significantly since the first recorded surgical day for spinal cord injury in the late 7th century. The techniques, instruments and implants have been improved over the years to better cope with the numerous spinal injuries and deformations that can occur due to trauma, disease or congenital disease. One type of spinal deformity, kyphosis, involves the prolapse of the vertebrae in the frontal direction of the body, often resulting from damage to the vertebral body itself. This failure can occur as a form of traumatic injury, such as a vertebral body fracture or rupture injury, or a non-traumatic deformation due to a tumor or degeneration in the vertebral body. Treatment of thoracic or lumbar spine kyphosis today is best done with an anterior approach today, especially to prevent some of the more serious complications associated with supporting or replacing a damaged vertebral body. it can. In most treatments for kyphosis, significant reconstruction of the spine from the anterior is required, most often with complete removal of the damaged vertebral body. In a typical anterior approach, the vertebral body and part or all of two adjacent vertebral discs are ablated. The remaining space is then deflected to steer the spine in its correct orientation. In many cases, the space is filled with a polymerizable paste or bone graft, often formed in the shape of a broken vertebral body. Often, the space is filled with self-bones, such as bones removed from the iliac bone. The polymerizable paste may include a PMMA bone cement. Once the cavity remaining after removal of the natural vertebral body has been filled, a osteosynthesis device is inserted between adjacent vertebrae that are not deformed to prevent relative movement between the vertebrae. This osteosynthesis device is essential for restoring the vertebral column to support loads on the thoracic or lumbar spine, and for increasing the likelihood and speed of bone graft material bonding with adjacent vertebral bodies. . If the bone graft and the material are sufficiently rigid, the osteosynthesis device will not normally experience additional mechanical stress. Known osteosynthesis devices are described in US Pat. No. 5,108,395 to Jean-Marie Laurain, the disclosure of which is incorporated herein by reference. This system is illustrated in FIGS. 1 and 2 of the present application. Referring first to FIG. 1, a damaged vertebra V _Three Is the damaged vertebral body C _Three Can be understood. The damaged vertebra V _Three And its adjacent disk D _Two , D _Three The two intact vertebrae V so that the _Two , V _Four An internal implant 1 is provided for cross-linking. The anterior implant 1 comprises a pair of clamps 2 which engage an intact vertebral body with a number of spikes 3. Furthermore, these clamps 2 are held in place by bone screws 5 extending through screw holes 11 and lateral projections 8 of the clamp. The implant 1 also includes a plate 6 configured to span between intact vertebrae, the plate 6 being rigid enough to support the load generated by the spine at that location. Each clamp 2 has a projecting threaded post 12 configured to extend through a corresponding opening 14 at each end of the plate 6. The nut 7 is adapted to engage its threaded post 12 to secure the plate 6 to each of the clamps 2. The surface of the clamp 2 has a notch 15 which engages a corresponding notch 16 at each end of the plate 6, thereby allowing the plate to be at a different directional angle to each of the clamps. . Clamp the healthy vertebral body V _Two , V _Four An opening 9 for receiving another bone screw 5 is formed to pass through the threaded post 12 of the clamp in order to ensure a secure fixation. One important feature of the system described in the above-mentioned U.S. Pat. No. 5,108,395 is that a notch 18 is formed in each of the clamps 2. These notches are two vertebrae V _Two , V _Four Between the forceps 19 used to provide a biasing force between the forceps. Once the clamp 2 has been secured to the corresponding healthy vertebra, as shown in FIG. 2, the forceps 19 are used to deflect and provide space for placement of the bone graft G. Once the bone graft is in place, the anterior plate 6 can be attached to each of the clamps 2 in the manner described above. Once the plate is in place, the deflecting forceps 19 are removed and the nut 7 is tightened to form a solid structure. The anterior structure illustrated in the above-mentioned U.S. Pat. No. 5,108,395 and FIGS. 1 and 2 of the present application is one system for anterior fixation using self or similar bone graft material. Other implants have been devised which use additional elements interposed between adjacent vertebrae in place of or in addition to conventional bone graft materials. One such device is described in U.S. Pat. No. 4,820,305 to Harms et al., Sold by Biederman Motech Company as "Harms Cage". This device inserts a hollow cylindrical mesh into the gap between adjacent vertebrae and places the bone graft material inside the hollow of the mesh. U.S. Pat. No. 5,192,327 to Brantigan shows a device similar to the "Herms Cage", consisting of a number of hollow elliptical implants with bone graft material disposed therein. Kale's EP 0,179,695 shows a rigid inert body having multiple passages extending between healthy vertebrae, into which bone growth material can be implanted. In addition, the device described in Kale's European patent includes a plate that spans between the vertebrae with holes for receiving bone screws. Another type of implant device that is particularly suitable for vertebral body replacement includes components of a substantially solid structure that completely occupies empty vertebral space. These devices are shown in U.S. Patent Nos. 4,554,914 to Kappa et al., 4,599,086 to Dotti, 4,636,217 to Ogilvie et al., And 5,147,404 to Dorney. Each of these devices is provided with a spike or similar mechanism that engages a healthy vertebral endplate to keep the implant in place. A similar structure is described in U.S. Pat. No. 5,062,850 to MacMillan et al., Which has an open space between the support columns of the axially fixed vertebral body prosthesis. In each of the above patents, the implant device must separately deflect the healthy vertebrae before inserting the device. The following patent shows a vertebral prosthesis that includes several features that cause the device to expand "in situ". For example, U.S. Pat. No. 4,932,975 to Mein et al. And U.S. Pat. No. 5,236,460 to Barber show prostheses that expand and contract through the introduction of hydraulic fluid. U.S. Pat. No. 4,401,112 to Lezian, U.S. Pat. No. 4,553,273 to Wu, and U.S. Pat. No. 4,657,550 to U.S. Pat. Further, the patent to Rezian shows a turnbuckle structure of this type which further comprises a plate with spikes engaged with the opposite healthy vertebra to reinforce the structure. In recent years, the use of an anterior approach has become more prominent for attaching instruments to the spine. As one proceeds with such an anterior approach, there is an increasing need to provide a vertebral replacement with all the advantages of anterior surgery without the disadvantages of some conventional devices. Each of the vertebral body substitutes described above has one or more disadvantages. For example, some devices do not have a means to synthesize bone between healthy vertebrae. Such devices do not have features that facilitate bone ingrowth or placement of bone grafts between adjacent healthy vertebrae. It will be appreciated that injecting a bone mass in place of a replacement vertebra can more permanently and stably correct kyphosis. As such, all vertebral replacements must be able to accommodate such features. Other vertebral prostheses cannot provide a means to adjust the size of the implant to accommodate a particular vertebral anatomy. Further, other devices do not include any additional securing means that facilitate providing a stable structure. Each of these needs and many other features are realized by a vertebral body replacement according to the present invention. SUMMARY OF THE INVENTION The present invention is directed to a vertebral replacement implant and assembly for securing an implant in a space formed by removing a vertebra between two complete vertebrae. In one form, the implant has a thin walled cylinder sized to occupy a substantial portion of the space between complete vertebrae. The cylinder is hollow and has a plurality of holes formed in the wall of the cylinder that communicate with the interior so as to allow for bone ingrowth once the implant is implanted. Both ends of the cylinder have a continuous threaded portion (preferably provided on the outer surface of the cylinder). The implant of the present invention further comprises a pair of end plates having surfaces oriented with respect to the opposite one of the complete vertebra when the prosthesis is implanted. Each of these end plates has a cylindrical portion extending from an end face, the cylindrical portion having a thread engaging a threaded end of the cylinder. Preferably, the screws of the end plate are inside the cylindrical part. In one form, these end plates are hollow in themselves, providing communication between the hollow interior of the cylinder and the adjacent complete vertebra. Alternatively, the present invention can add an end cap to the implant so that the end face of the endplate can be closed against the adjacent vertebra to provide additional support for weak vertebrae. is there. Another feature of the present invention is that it provides a means of securing the cylinder to each of the end plates and preventing loosening of the mating screws of the three components of the implant. In one form, the securing means includes a hole in a threaded portion of the end plate that is threaded to accept a set screw. Preferably, two set screws are screwed into these two holes in the end plate so that clamping pressure can be applied to the cylinder engaged with the end plate. In another embodiment, the fixing means is a crimpable cylindrical portion of the end plate. In one form, the cylindrical portion has an annular ring with a crimp notch. Applying a crimping force around the annular ring narrows the notch, thereby reducing the circumference of the cylindrical portion and tightly engaging the threaded portion of the cylindrical body. Another aspect of the invention is to provide a means for connecting the implant to a longitudinal member that extends outside the space created by the removed vertebra. The longitudinal member may be a plate or rod secured in a known manner to the adjacent complete vertebra. This longitudinal member is preferably used to facilitate deflection of the complete vertebra to insert a vertebral replacement implant. In one embodiment, the connection means has a clamp configured to be clamped to the longitudinal member. The clamp supports a screw that is oriented toward the replacement implant when interposed between the complete vertebrae. The cylinder of the implant has a number of holes threaded to receive connecting screws. The clamp preferably slides along the length of the longitudinal implant to facilitate alignment of the thread with a number of threaded holes in the cylinder. Further, the clamp has a circular seat and the screw has a round head so as to allow changing the angular orientation of the screw with respect to the longitudinal member. In another embodiment, the connection means comprises an arm extending from a flange of the end plate. The free end of the arm has an opening through which the longitudinal member extends. A set screw traverses this opening and secures the longitudinal member to the longitudinal member of the end plate. It is an object of the present invention to provide a vertebral body replacement implant configured to support the space formed by a damaged or diseased vertebra. One object is to provide an implant that is easily adjustable so that the overall length of the implant can be varied, depending on the height position of the vertebra where the implant is interposed. It is a further object of the implant of the present invention to allow this length adjustment and to provide a means for securing the components so as to be disengaged, i.e., not unscrewed. It is. Another object of the present invention is achieved by providing a means for connecting a vertebral replacement implant to a longitudinal member extending along the length of the spine between adjacent complete vertebrae. This longitudinal member can be used to deflect the space created by the removed vertebra to facilitate insertion of a replacement implant. Yet another object is to provide an implant that can contain bone growth material to facilitate fusion of the height location where the device is mounted. One advantage of the vertebral body of the present invention is that it provides a solid implant that supports the load of the spine while waiting for the bone growth material to fuse between the complete vertebrae. Yet another advantage is that the implant can be easily adjusted to accommodate space at different heights of the vertebra. Other objects and advantages of the present invention can be understood by referring to the following description of the invention and the accompanying drawings and claims. DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a spinal osteosynthetic implant according to prior art US Pat. No. 5,108,395. FIG. 2 shows a portion of FIG. 1 with the addition of a device that allows placement of an implant between vertebrae while holding a clamp associated with the prior art device of US Pat. No. 5,108,395. is there. FIG. 3 is an exploded perspective view of a vertebral body replacement assembly according to one embodiment of the present invention. FIG. 4 is an end view of an end plate used in connection with the vertebral body replacement assembly shown in FIG. FIG. 5 is a side view of an end plate used with the vertebral body replacement assembly of FIG. FIG. 6 is an exploded perspective view showing one component of a clamp assembly used with the vertebral body replacement assembly shown in FIG. FIG. 7 is a side view of a vertebral body replacement assembly according to another embodiment of the present invention, particularly suitable for use with an elongated rod that spans a vertebral portion. FIG. 8 is an end view of the vertebral body replacement assembly shown in FIG. 7 with the assembly in place above a complete vertebra. FIG. 9 is a side view of the assembly shown in FIG. 7 when engaged with an elongated rod. FIG. 10 is a perspective view of an end plate used with the vertebral body replacement assembly shown in FIG. FIG. 11 is an end view of one particular end plate for use with the vertebral body replacement assembly shown in FIG. 3 in the thoracic spine. DESCRIPTION OF THE PREFERRED EMBODIMENTS For the purpose of facilitating the understanding of the principles of the present invention, the following description will be given of the embodiments shown in the drawings using specific terms. However, this is not intended to limit the scope of the invention in any way, and variations and further modifications of the illustrated apparatus, and further applications of the illustrated principles of the invention, are not intended to It will be understood by those of ordinary skill in the art that Referring first to FIG. 3, a vertebral body replacement assembly 20 according to one embodiment of the present invention is illustrated. The assembly 20 generally includes a threaded cylinder 21, a threaded end plate 22, and an end cap 23. Also provided is a set screw 24 as one embodiment of means for securing each of the end plates 22 to the corresponding end of the cylindrical body 21. In one specific embodiment, the set screw 24 is a breakable locking screw whose head will shear when the tightening torque limit is reached. Such a locking screw is disclosed in co-pending French patent application No. 94 10 377 filed on Aug. 29, 1994. The threaded cylinder 21 is formed by a cylindrical wall 25 defining a hollow cavity 26. The cavity is configured to receive an osteosynthetic material, which can be in the form of a self or similar material. The cylindrical wall 25 is provided with a plurality of holes 28 communicating with the cavity 26. These holes provide a passageway for bone or tissue to grow in and further enhance the stability of the implant. The cylindrical wall 25 is configured to engage the support assembly 55 and has a second plurality of threaded holes 29 formed substantially midway between the implants, as described in more detail below. I have. In one important feature of the cylinder 21, both ends of the cylindrical wall 25 are formed with external threads 32. In one specific embodiment, the screws 32 extend from each other end over most of the length of the threaded cylinder 21 and are configured to engage the threaded end plate 22. ing. Each of the end plates is provided with a flange 35, which is preferably shaped to cover substantially the load bearing area of the adjacent complete vertebral body end plate. The cylindrical body 37 is integrally formed with a flange 35 which extends in the direction of the threaded cylindrical body 21 when the end plate 22 is placed in the cut vertebral space. Each cylindrical body 37 of the end plate has a number of threaded holes 39 therein for receiving the set screw 24. The cylindrical body 37 and the flange 35 of the end plate 22 define a through hole 40. On the inner surface of the hole 40, there is provided a female screw 41 configured to engage with the male screw 32 of the cylindrical body 21. In a preferred embodiment, the screw 41 extends at least along the entire length of the cylinder 37, and preferably extends into the flange 35. Further details of the end plate 22 can be seen in FIGS. As shown in FIG. 5, the cylindrical body 37 is integrally formed with a flange 35 so as to define an angle 43 of lordosis. This angle corresponds to the vertebra V shown in FIG. _Three Vertebral body replacement assembly 20 to replace damaged vertebrae such as, and to maintain the normal anterior curvature of the spine at its height. is there. An end face 36 of the flange 35 is provided with a conduit hole 45 extending through the flange. These holes 45 are intended to provide a passageway that conduits the space between adjacent vertebrae. The end face 36 can be provided with four spikes, such as the spike 91 shown in the embodiment of FIG. Alternatively, a spike 120 (FIG. 3) having a threaded stem 121 that engages a threaded hole 46 formed in the end face 36 may be provided. In each case, the spikes (91, 120) are configured to penetrate the endplates of adjacent vertebrae to help maintain the implant in place at the "site". The end face is further provided with a mounting slot 47 traversing the flange 35 and straddling the chord of the internal hole 40. A hole 48 extends through each of the mounting slots. The cylindrical body 37 of the end plate 22 is provided with a mounting notch 49 aligned with each hole 48 of the mounting slot 47. These slots 47, holes 48, and cutouts 49 are configured to support the end cap 23, as described herein. Referring again to FIG. 3, the end cap 23 includes a generally rectangular support bar 50 mounted across the chord of a flat circular plate 52 of the end cap. Each end of the support bar 50 has a protrusion 51 projecting outward. Each of the projections 51 is sized to be received in a corresponding hole 48, while the support bar 50 itself is configured to fit into the mounting slot 47 of the flange 35. Further, each of the projections 51 slides conveniently into a corresponding mounting notch 49 of the cylindrical body 37. In this way, in particular, the complete vertebra V where the replacement object assembly is adjacent _Two , V _Four When placed between the end caps 23, the end cap 23 is held in place. The end cap 23 provides additional support for the implant between adjacent complete vertebrae. This end cap may be omitted if it is desired for the bone to grow between adjacent vertebrae and through the replacement object. Alternatively, the plate 52 of each end cap 23 allows bone ingrowth between the endplates of the vertebra and the bone growth material disposed within the threaded cylinder 21. You can also drill holes to get. In a preferred embodiment, the endplates are solid and shown as providing maximum load bearing capacity for loads along the length of the vertebral column. In the illustrated embodiment, the screws 32 provided on the cylindrical replacement body are male threads, while the end plate screws 40 are female threads. Alternatively, the end plate cylinder 37 may have external threads and the cylindrical alternative may have internal threads in the cavity 26. In this latter case, the inner diameter of the cylinder is naturally slightly larger than the outer diameter of the end plate cylinder. In a preferred embodiment, the cylindrical wall forming implant 21 can be relatively thin when compared to prior art alternatives. In one particular embodiment, the thickness of this wall is 1 mm. Since the primary load supported by the implant is not a bending load but an axial compression force, a thinner cylinder is suitable and even more desirable. The implant 21 also preferably has a number of holes 28, 29 to promote tissue ingrowth and ducting, thereby increasing the stability of the structure after fusion. In one particular embodiment, the total area of the plurality of holes is at least 25% of the surface area of the cylinder 21. In use, the vertebra V shown in FIG. _Three Remove damaged vertebrae such as. In one embodiment, the clamp 2 of the internal implant 1 shown in FIGS. 1 and 2 engages the complete vertebral body in the manner shown in FIG. Also, as shown in FIG. 2, the forceps 10 can be used to deflect the complete vertebra to allow the vertebral replacement assembly 20 to be implanted. In a preferred method, the optimal height of the vertebra is set, and the threaded cylinder 21 and the threaded end plate 22 are attached together to achieve the proper height. In particular, each of the end caps can be screwed onto the threaded cylinder 21 until the desired height is obtained. It is important that the bottom edge 44 of the flange 35 of each endplate be oriented in substantially the same direction between the two threaded endplates 22. This orientation is important because the replacement assembly 20 is located between the two complete vertebrae abutting the endplates of these vertebrae. In order to maintain the maximum load bearing function, the flange 35, in particular the end face 36, should be in the shape of a vertebral body against which the end plate abuts, and its dimensions should be such that the area of the complete vertebra end plate is as small as possible. It is set to occupy a wide area. It is preferable to provide three types of such shapes so as to be able to cope with the anatomical differences of the vertebral bodies at the waist, chest-hip and waist level. The configuration of the flange 35 shown in FIG. 4 is applicable to the thoracic-lumbar vertebra. A smaller and more circular configuration is also possible for the flange 35 'shown in FIG. 11 to be implanted at chest level. The flange 35 'is also shown as having a relief radius 38 to allow for increased clearance between the flange and the dural space containing the spinal cord. This relief radius 38 is preferably included in all three types of end plate flange shapes. In one particular embodiment, the external threads 32 of the threaded cylinder 21 are formed in opposite directions so that only the cylinder can be rotated to draw or separate the end plates together. Thus, when the cylinder is rotated in one direction, the threads 32 at each end engage the female threads 41 on each end cap 23 in the correct direction to pull the end caps together. Alternatively, the direction of the screws 32 may be equal at each end, such that each end cap needs to be individually screwed into the cylinder 21 in the opposite direction. The disadvantage of this arrangement is that it becomes more difficult to adjust the overall height of the assembly 20 while maintaining the proper orientation of each of the lower edges 44 of the end faces 36. One advantage is that the assembly does not loose its own screws "on site." Once the end plate and the threaded cylinder have been engaged in the proper orientation to allow for the correct height, the set screw 24 is threaded into the appropriate opening of the threaded opening 39 of the cylinder 37 of the end plate 22. , So that the set screw 24 extends so as to contact the threaded cylinder 21. A set screw 24 (which can be a breakable locking screw as described above) applies clamping pressure to the cylinder 21 to hold the cylinder in place. Thus, the set screw 24 provides a means of securing the components together and preventing the cylinder 21 from rotating with respect to any of the end plates 22. Preferably, two set screws are used on each end plate 23 to ensure that the associated ends of the threaded cylinder 21 are securely fixed. The hole 28 in the threaded cylinder has a smaller diameter than the set screw 24 to ensure that the set screw 24 is retained on the body 21. Once the cylinder and endplate have been secured in their proper height dimensions, the bone graft material can be inserted into the hole 40 in the endplate and into the cavity 26 of the cylinder 21. After the interior of these components has been completely filled with the bone graft material, the ends 32 are extended so that the projections 51 extend through the holes 48 and the support bars 50 extend through the mounting slots 47 in each end plate. Place in place. Next, the deflected vertebra V _Two , V _Four The alternative assembly 20 can be located between the two. Once the assembly is in place and each end face 36 of the end plate 22 is properly oriented on the vertebral end plate, the biasing forceps 19 are removed and the assembly 20 is removed Be clamped in place between the two vertebrae. To further ensure that the replacement assembly 20 does not move or slide into place between the full vertebrae, a support assembly 55 may be provided. In the preferred embodiment, the support assembly 55 is configured to engage a clamp 2 used with the prior art anterior implant system illustrated in FIGS. The support assembly 55 may also include other front plates, such as the Z-plate ATL sold by Daneck Medical, Inc., or a rod system, such as the sofa mower SNC CD Hoff system. It is also possible to use with. In particular, the support assembly has a stabilizing plate 57, which can be of the same form as the plate 6 shown in FIG. 1 and which has a cut in the bottom of the end of the plate. To The means for connecting the vertebral replacement object assembly 20 to the plate 57 includes a clamp assembly 59 that securely grips the plate 57 and supports a locking screw 69. The clamp assembly 59 has a pair of clamp halves 60, which are preferably C-shaped to hold and support the plate 57. Each of the clamp halves 60 has a hole (not shown) for receiving the threaded rod 63 of the adjustment plate 62. A nut 64 is screwed onto the rod 63 to pull the clamp halves 60 together around the stabilizing plate 57. Details of this adjustment plate 62 are more clearly shown in FIG. The adjustment plate has a threaded rod 63 extending from a face 65 of the plate 62. The plate 62 has a through hole 67 having a circular seating surface 68. The round head 70 of the locking screw 69 is received in the through hole 67. The locking screw 69 has a hexagonal recess 71 in its head for receiving a driver tool. The locking screw 69 has a threaded shaft portion 73 adapted to engage with one of the threaded holes 29 of the threaded cylindrical body 21. A guide hub 75 having a smaller diameter than the threaded shaft portion 73 is provided to facilitate guiding the locking screw 69 to a predetermined position. The locking screw 69 preferably has a smooth shaft 74 between the screw head 70 and the threaded shaft 73. In use, the clamp half 60 is temporarily attached to the stabilizing plate 57, which is not clamped. This stabilizing plate 57 can then be engaged with the clamp 2 at each of the secure vertebral bodies and secured in place by a corresponding nut such as the nut 7 shown in FIG. Thus, with the stabilizing plate 57 attached between the deflected vertebrae, the biasing forceps 19 can be removed and the entire load of the spine can be carried by the replacement assembly 20. Once the biasing forceps have been removed, the clamp half 60 is adjusted along the length of the plate 57 and the locking screw 69 is aligned with the appropriate one of the threaded holes 29 in the threaded cylinder 21. You can make it. The spherical contact between the head 70 of the locking screw 69 and the circular seat 68 of the adjustment plate 62 allows the locking screw to take any angle necessary to engage the threaded hole 29. to enable. When so aligned, the locking screw 69 can be easily screwed into one of the holes 62 until locked between the adjustment plate 62 and the threaded cylinder 21. At this point, the clamp half 60 can be completely clamped on the plate 57 by tightening the nut 64 onto the threaded rod 63. In another embodiment of the present invention, vertebral body replacement assembly 80 is configured to connect to an elongated deflection rod or compression rod. In this embodiment, the assembly 80 has both end plates 83 configured to be screwably engaged with the cylindrical body 21 (the cylindrical body 21 is in all respects, as shown in FIG. 3). Is substantially the same as the cylindrical body 21 described above). In this embodiment, the end plate 83 has a flange 85 and a cylindrical body 87 protruding from the end plate. The cylindrical body 87 has a screw hole 88 formed to receive the male screw 32 of the cylindrical body 21. As in the case of the conventional end plate, the end plate 83 has a plurality of conduit holes 89 formed in the flange 85. The end face 86 of the flange 85 has a number of spikes 91 protruding from the end face. These spikes are configured to penetrate the endplates of adjacent vertebral bodies to help keep the implant in place "on site." As shown in FIGS. 7 and 8, the end plate 83 has an arm 94 projecting from a flange 85, one component of the means for connecting the implant to a longitudinal member (such as a rod 105). doing. A rod hole 95 is formed at a position adjacent to the free end 94 a of the arm 94, and a set screw hole 96 traverses the rod hole 95 from the free end of the arm 94. A set screw 98 for clamping the rod extending therethrough is provided to engage within the set screw hole 96. The method of using the replacement assembly 80 in this embodiment is shown in FIGS. In particular, the end plate 83 engages the appropriate vertebra via a spike 91. These plates are also configured to define an angle 115 that can correspond to the appropriate spinal anatomy at a particular vertebral level. Via bone screws 108, a deflection plate 107 is attached to each of the complete vertebrae. The plate 107 has a collar 109 formed integrally with the plate, and the deflection rod 105 passes through the collar 109. The deflection rod extends so as to pass through each of the rod holes 95 of the arm 94 of the end plate 83. Set screws 98 secure these end plates in place with the rod extending through each of the holes. A properly shaped instrument capable of engaging each collar 109 of the deflection plate 107 mounted within each vertebra can deflect the adjacent vertebra. Set screws (not shown) can be provided to secure the rod 105 inside each collar 109. A method for fixing the end plate to the threaded cylinder will be described with reference to FIGS. 7, 9 and 10. In particular, fixing means (in the form of crimping grooves 100 around the diameter of the cylindrical body) is provided on the end plate 83, specifically on the cylindrical body 87 of the end plate. On both sides of the cylindrical body, crimp notches 101 are formed in the grooves 100. In short, the crimp notch is a gap on the outer periphery of the groove 100. The crimp notch provides a gap that can be closed by a suitable gripping tool that grips the entire circumference of crimp groove 100. When the crimping tool is tightened, these notches 101 close when the grooves move together in the direction of arrow 102. It can be seen that this form of crimping is an alternative to the set screw 24 (the screw disclosed with respect to the previous embodiment) that secures the end plate to the threaded cylinder. Although the invention has been illustrated in the drawings and has been described in detail in the above description, this is by way of example only and is not intended to limit the features of the invention, but to make all changes and modifications belonging to the invention. It should be understood that the examples are intended to include the subject of protection.

[Procedure of Amendment] Article 184-8, Paragraph 1 of the Patent Act [Submission date] January 20, 1997 [Correction contents]                              The scope of the claims   1. Formed by one or more removed vertebrae between adjacent complete vertebrae Vertebral replacement implant interposed in the space that was   Alternative with two ends sized to span part of the space between the complete vertebrae The alternative object, wherein the alternative object has a first screw formed at each of the ends. The alternative object further comprises a cylindrical wall defining a hollow interior, the cylindrical wall penetrating therethrough. A plurality of holes, the holes communicating with the hollow interior of the replacement object; Promotes tissue ingrowth into the replacement object,   The replacement object has an outer surface area, and the plurality of holes have about 25% of the outer surface area. The above effective area is defined,   When the implant is interposed in the space, that of the complete vertebra A pair of end plates each having an end surface in contact with one of the end plates, each of the end plates being A cylindrical portion extending integrally therewith, the cylindrical portion being a first portion on the replacement object. A second screw configured to threadably engage the screw, wherein each of the end plates is A vertebral replacement implant further defining a through hole opening in the end face and in the cylindrical portion. Plant.   4. 2. A vertebral replacement implant according to claim 1 wherein said intermediate portion of said replacement object A vertebral replacement implant having an empty interior open at the ends.   5. 2. A vertebral replacement implant according to claim 1, wherein the replacement object is hollow. A vertebral replacement implant having a cylindrical wall defining an interior and open at both ends; And   6. 6. The vertebral replacement implant of claim 5, wherein each of the endplates is A vertebral replacement implant defining a through hole opening in the end face and at the cylindrical portion And   7. 7. A vertebral replacement implant according to claim 6, wherein the implant is on the replacement object. A first screw is a male screw and the second screw on the cylindrical portion of the pair of end plates A vertebral replacement implant, wherein is a female screw.   8. A vertebral replacement implant according to claim 1 wherein said end surface is An end cap for closing one of the holes in the end plate; A vertebral replacement implant having means for supporting a head cap over the endplate.   9. 2. A vertebral replacement implant according to claim 1, wherein said implant is on said replacement object. A first screw is a male screw and the second screw on the cylindrical portion of the pair of end plates A vertebral replacement implant, wherein is a female screw. 10. 2. A vertebral replacement implant according to claim 1, wherein the replacement object is the end piece. Means for securing to each of the plates to prevent loosening of said first and second screws. A vertebral replacement implant. 11. A vertebral replacement implant according to claim 10, wherein the fixation means comprises:   A number of openings defined in the cylindrical portion of each of the pair of end plates;   A member extending through one of the plurality of holes and capable of contacting the replacement object. Vertebral replacement implant. 12. A vertebral replacement implant according to claim 11,   The member is a set screw,   The multiple openings are adapted to receive the set screw in a threaded engagement. A vertebral replacement implant, where the spine is formed. 13. 12. The vertebral replacement implant of claim 11, wherein the plurality of openings are A vertebral replacement implant defined in the endplate with the second screw. 14． 2. The vertebral replacement implant of claim 1, wherein each of the endplates is A flange defining an end face, wherein the flange is radially outward from the cylindrical portion. And the flange is shaped to form a portion of the complete vertebra with which the end plate is in contact. A vertebral replacement implant that defines a shape substantially corresponding to the shape. 15. 15. The vertebral replacement implant of claim 14, wherein the flange has a through hole. A vertebral replacement implant that defines a number of conduit holes through which it passes. 16. Formed by one or more removed vertebrae between adjacent complete vertebrae Vertebral replacement implant interposed in the space that was   Alternative object with both ends sized to span part of the space between complete vertebrae Said replacement object having a first screw formed on each of said ends;   When the implant is interposed in the space, that of the complete vertebra A pair of end plates each having an end surface in contact with one of the end plates, each of the end plates being A cylindrical portion extending integrally therefrom, wherein said cylindrical portion is provided on said replacement object. A second screw configured to threadably engage the first screw, wherein each of the end plates Each further define a through hole opening in said end face and in said cylindrical portion, An end cap that closes one of the holes in the end plate at an end face; But,     A plate shaped to correspond to the hole opening formed in the end plate,     A support bar attached to the end plate,   The end plate has a slot defined in the end surface for receiving the support bar. And the plate of the end cap is flush with the end face of the end plate. A vertebral replacement implant positioned. 17． Formed by one or more removed vertebrae between adjacent complete vertebrae Vertebral replacement implant interposed in the space that was   Alternative object with both ends sized to span part of the space between complete vertebrae Said replacement object having a first screw formed on each of said ends;   When the implant is interposed in the space, each complete vertebra A pair of end plates having an end surface in contact with each one of the end plates, each of the end plates being A cylindrical portion extending integrally from the end surface, wherein the cylindrical portion is disposed on the substitute object. A second screw configured to threadably engage with the first screw of Each of the plates further defines a through hole opening in said end face and in said cylindrical portion; The length of each cylindrical portion of the end plate protruding from the end face, and a part of the length And a crimp notch formed along the   The cylindrical portion is deformed at the crimp notch and closes the notch, When the replacement object is threadably engaged with the cylindrical portion of the end plate, A vertebral replacement implant, wherein the outer circumference of the surrounding cylindrical portion is reduced. 18. The vertebral replacement implant of claim 1, wherein each of the pair of end plates is Multiple protruding from the end surface to be implanted in a corresponding one of the adjacent complete vertebrae A vertebral replacement implant with a number of spikes. 19. Formed by one or more removed vertebrae between adjacent complete vertebrae Vertebral replacement implant interposed in the space that was   Alternative object with both ends sized to span part of the space between complete vertebrae Said replacement object having a first screw formed on each of said ends;   When the implant is interposed in the space, each complete vertebra A pair of end plates having end surfaces in contact with respective ones of said end plates, each of said end plates being A cylindrical portion extending integrally therefrom, wherein said cylindrical portion is provided on said replacement object. A second screw configured to threadably engage the first screw, wherein each of the end plates Each further define a through hole opening in the end face and in the cylindrical portion, the pair of The end face of each of the end plates defines a number of threaded holes, and the adjacent complete vertebrae Comprising a number of spikes protruding from said end face for implantation in a corresponding one;   Each of the spikes is associated with the threaded hole in the end face of each of the end plates. A vertebral replacement implant comprising a threaded post configured to fit. 20. Formed by one or more removed vertebrae between adjacent complete vertebrae Vertebral replacement implant interposed in the space that was   Alternative object with both ends sized to span part of the space between complete vertebrae Said replacement object having a first screw formed on each of said ends;   When the implant is interposed in the space, each complete vertebra A pair of end plates having an end surface in contact with each one of the end surfaces, each of the end plates being A cylindrical portion extending integrally therefrom, wherein said cylindrical portion is provided on said replacement object. A second screw configured to threadably engage the first screw, wherein each of the end plates Each further defining a through hole opening in said end face and in said cylindrical portion; Each of the cylindrical portions extends from the end surface at a non-perpendicular angle, the angle comprising: A vertebrae corresponding to the curvature of the spine in the space formed by the removed vertebrae; Bone replacement implant. 21. Formed by one or more removed vertebrae between adjacent complete vertebrae Vertebral replacement implant interposed in the space that was   Alternative object with both ends sized to span part of the space between complete vertebrae Said replacement object having a first screw formed on each of said ends;   When the implant is interposed in the space, that of the complete vertebra A pair of end plates each having an end surface in contact with one of the end plates, each of the end plates being A cylindrical portion extending integrally therefrom, wherein said cylindrical portion is provided on said replacement object. A second screw configured to threadably engage the first screw, wherein each of the end plates Each further defining a through hole opening in said end face and in said cylindrical portion; Each define a flange defining the end face and extending outwardly from the cylindrical portion. In addition,   The flange includes an arm projecting from the cylindrical portion;   The arm is adapted to engage a longitudinal member disposed along the length of the spine. Vertebral replacement having a free end configured to extend beyond the adjacent complete vertebra For implants. 22. 22. The vertebral replacement implant of claim 21, wherein the arm comprises the arm. A vertebral replacement implant defining a hole in the free end to receive a longitudinal member And 25. Assembly for removing adjacent intermediate vertebrae after removing damaged intermediate vertebrae And then   A vertebral replacement implant, wherein the implant comprises:     Dimensioned to span a portion of the space created by removal of the damaged vertebra An alternative object having both ends, wherein a first screw is formed and multiple along the outer periphery thereof. Said alternative body in which a number of threaded holes are formed;     When the implant is interposed in the space, the complete vertebrae A pair of end plates having end surfaces that contact each one,   Each of the end plates has a cylindrical portion extending integrally from the end surface,   The cylindrical portion is configured to threadably engage the screw on the replacement object. Having a second screw,   Outside the space created by removing the damaged vertebrae, Elongate sized to span and completely engage abutting complete vertebra A longitudinal member;   A clamp connecting the vertebral replacement implant to the longitudinal member.   The clamp includes a plate defining a hole having a circular seat;   Attached to the clamp with a screw engaging one of the threaded openings Screw having a round head configured to engage the circular seat. An assembly comprising the screw. 26. Assembly for removing adjacent intermediate vertebrae after removing damaged intermediate vertebrae And then   A vertebral replacement implant, wherein the implant comprises:     Dimensioned to span a portion of the space created by removal of the damaged vertebra An alternative object having both ends, wherein said alternative object is formed with a first screw;     When the implant is interposed in the space, the complete vertebrae A pair of end plates each having an end surface contacting one of said end plates, each of said end plates being The pair of end plates having a cylindrical portion extending integrally from a surface thereof. A second screw configured to threadably engage the screw on the replacement object. Wherein each of said end plates is a flange defining said end surface, said cylindrical portion Comprising the flange extending outwardly from the minute,   Outside the space created by removing the damaged vertebrae, Elongate sized to span and completely engage abutting complete vertebra A longitudinal member and a connection connecting the vertebral replacement implant to the longitudinal member And means,   An arm integral with the flange and projecting from the cylindrical portion Wherein the arm is adapted to engage the longitudinal member so that the adjacent full An assembly having a free end configured to extend beyond a natural vertebra. 27. 27. The assembly of claim 26 for securing adjacent complete vertebrae,   A second arm formed at the free end to receive the longitudinal member; One hole and a set screw hole formed at the free end so as to traverse the first hole. Define   The connection means has a set screw screwed into the set screw hole,   A tip wherein the set screw engages a longitudinal member extending through the first hole An assembly having: 28. In the space formed by the removed vertebrae between adjacent complete vertebrae To make an implant for vertebral replacement   A length that has both ends and is dimensioned to span a portion of the space between the complete vertebrae An alternative object having   When the implant is interposed in the space, each complete vertebra A pair of end plates each having an end surface contacting a respective one of the end plates; The pair of end plates having an engaging portion extending integrally from the end surface,   Engage the end plate with the replacement object at a variable position along the length of the replacement object Between the opposite ends of the replacement object and the engagement portions of each of the end plates. With a screw   The alternative object is replaced with the mating screw to prevent the engagement screw from being disengaged. Means for securing to each of the end plates. 31. Intervening in the space formed by the removed vertebra between two complete vertebrae Vertebral replacement implants   A thin-walled cylinder defining a hollow interior, wherein the wall of the cylinder is Defining a plurality of holes having a total area at least equal to 25% of the outer surface area;   The cylindrical body has opposite ends having continuous threads formed at each of the opposite ends;   A pair of end plates, each of which has an implant interposed within said space. A flange that defines an end surface that contacts the respective one of the full vertebrae when retracted Formed by   Each of the end plates further comprises a cylindrical portion projecting integrally from the flange;   The cylindrical portion engages the threads at the ends of the thin walled cylinder. To define a continuous screw   When each of the end plates is threadably engaged with the end plate, the meat Defining a through hole communicating with the hollow interior of the thin cylinder,   The length of the cylindrical portion having a length that the cylindrical portion protrudes from the end face; Defining a crimp notch formed along part of the   The cylindrical portion deforms at the crimp notch and closes the notch, thereby When the cylindrical body is threadably engaged with the cylindrical portion of the end plate, around the cylindrical body Vertebral replacement implant wherein the outer circumference of the cylindrical portion is reduced G. 33. 2. The vertebral replacement implant of claim 1, wherein a portion of the plurality of holes is A vertebral replacement implant extending through the first screw of the replacement object. 34. A vertebral replacement implant according to claim 7, wherein the replacement object is hollow. Having a cylindrical wall defining the interior,   The cylindrical wall defines a plurality of through holes;   The hole communicates with the hollow interior of the replacement object to allow tissue into the replacement object. A vertebral replacement implant that promotes head growth. 35. 35. The vertebral replacement implant of claim 34, wherein a portion of the plurality of holes is provided. A vertebral replacement implant extending through the external thread of the replacement object. 36. A vertebral replacement implant according to claim 28,   The engagement portion of the pair of end plates has at least one threaded through hole;   When the fixing means engages the cylindrical body with the end plate by screwing, Having a set screw screwed into the opening and in contact with the replacement object , Vertebral replacement implant.

────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Chevalier, Jean-Louis             F-62155, Merlimont, France             —Plage, Avignon D'artois 57 (72) Morau, Jean-Charles             France F-62520, Le Touquet             —Paris-Plage, Avne des Cana             Dijan, Virula la Musarde

Claims (1)

[Claims]   1. Formed by one or more removed vertebrae between adjacent complete vertebrae Vertebral replacement implant interposed in the space that was   Alternative object with both ends sized to span part of the space between complete vertebrae Said replacement object having a first screw formed on each of said ends;   When the implant is interposed in the space, that of the complete vertebra A pair of end plates each having an end surface in contact with one of the end plates, each of the end plates being A cylindrical portion extending integrally therewith, the cylindrical portion being a first portion on the replacement object. A second screw configured to threadably engage the screw, wherein each of the end plates is A vertebral replacement implant further defining a through hole opening in the end face and in the cylindrical portion. Plant.   2. 2. A vertebral replacement implant according to claim 1, wherein the replacement object is hollow. A cylindrical wall defining an interior, the cylindrical wall defining a plurality of holes therethrough, the holes comprising: Communicates with the hollow interior of the replacement object to facilitate tissue ingrowth into the replacement object. Promotes vertebral replacement implants.   3. 3. The cylinder defining a vertebral replacement object according to claim 2 and defining the replacement object. The wall has a surface area, and the plurality of holes define an effective area of at least 25% of the surface area. Vertebral replacement object.   4. 3. A vertebral replacement implant according to claim 2, wherein the intermediate portion of the replacement object is provided. A vertebral replacement implant having an empty interior open at the ends.   5. 2. A vertebral replacement implant according to claim 1, wherein the replacement object is hollow. A vertebral replacement implant having a cylindrical wall defining an interior and open at both ends; And   6. 6. The vertebral replacement implant of claim 5, wherein each of the endplates is A vertebral replacement implant defining a through hole opening in the end face and at the cylindrical portion And   7. 7. A vertebral replacement implant according to claim 6, wherein the implant is on the replacement object. A first screw is a male screw and the second screw on the cylindrical portion of the pair of end plates A vertebral replacement implant, wherein is a female screw.   8. A vertebral replacement implant according to claim 1 wherein said end surface is An end cap for closing one of the holes in the end plate; A vertebral replacement implant having means for supporting a head cap over the endplate.   9. 2. A vertebral replacement implant according to claim 1, wherein said implant is on said replacement object. A first screw is a male screw and the second screw on the cylindrical portion of the pair of end plates A vertebral replacement implant, wherein is a female screw. 10. 2. A vertebral replacement implant according to claim 1, wherein the replacement object is the end piece. Means for securing to each of the plates to prevent loosening of said first and second screws. A vertebral replacement implant. 11. A vertebral replacement implant according to claim 10, wherein the fixation means comprises:   A number of openings defined in the cylindrical portion of each of the pair of end plates;   A member extending through one of the plurality of holes and capable of contacting the replacement object. Vertebral replacement implant. 12. A vertebral replacement implant according to claim 11,   The member is a set screw,   The multiple openings are adapted to receive the set screw in a threaded engagement. A vertebral replacement implant, where the spine is formed. 13. 12. The vertebral replacement implant of claim 11, wherein the plurality of openings are A vertebral replacement implant defined in the endplate with the second screw. 14． 2. The vertebral replacement implant of claim 1, wherein each of the endplates is A flange defining an end face, wherein the flange is radially outward from the cylindrical portion. And the flange is shaped to form a portion of the complete vertebra with which the end plate is in contact. A vertebral replacement implant that defines a shape substantially corresponding to the shape. 15. 15. The vertebral replacement implant of claim 14, wherein the flange has a through hole. A vertebral replacement implant that defines a number of conduit holes through which it passes. 16. A vertebral replacement implant according to claim 15,   The end cap is     A plate shaped to correspond to the hole opening formed in the end plate,     Said end plate;     A support bar attached to the end plate,   The end plate has a slot defined in the end surface for receiving the support bar. And the plate of the end cap is flush with the end face of the end plate. A vertebral replacement implant. 17． A vertebral replacement implant according to claim 10,   The cylindrical portion of each of the end plates has a length protruding from the end face;   The fixing means includes a crimp cut formed along a part of the length of the cylindrical portion. With a chip,   The cylindrical portion is deformed by the crimp notch and closes the notch. When the alternative object is threadably engaged with the cylindrical portion of the end plate, the alternative A vertebral replacement implant, wherein the outer circumference of the cylindrical portion around the body is reduced G. 18. The vertebral replacement implant of claim 1, wherein each of the pair of end plates is Multiple protruding from the end surface to be implanted in a corresponding one of the adjacent complete vertebrae A vertebral replacement implant with a number of spikes. 19. A vertebral replacement implant according to claim 18,   Said end face of each of said pair of end plates defines a number of threaded holes;   Each of the plurality of spikes is threaded on the end face of each of the end plates. A vertebral replacement implant having a threaded post configured to engage a puncture G. 20. 2. A vertebral replacement implant according to claim 1, wherein each of said endplates comprises A cylindrical portion extends from the end face at a non-perpendicular angle, the angle being removed. Vertebral replacement implant corresponding to the curvature of the spine in the space formed by the vertebrae plant. 21. 2. The vertebral replacement implant of claim 1, wherein each of the end plates is anterior. A flange defining the end face and extending outwardly from the cylindrical portion;   The flange includes an arm projecting from the cylindrical portion;   The arm is adapted to engage a longitudinal member disposed along the length of the spine. Vertebral replacement having a free end configured to extend beyond the adjacent complete vertebra For implants. 22. 22. The vertebral replacement implant of claim 21, wherein the arm comprises the arm. A vertebral replacement implant defining a hole in the free end to receive a longitudinal member And 23. Assembly for removing adjacent intermediate vertebrae after removing damaged intermediate vertebrae And then   A vertebral replacement implant, wherein the implant comprises:   Sized to span a portion of the space formed by removal of the damaged vertebra; An alternative object having both ends, wherein the alternative object is formed with a first screw;   That of the complete vertebra when the implant is interposed in the space A pair of end plates having end surfaces that contact each one,   Each of the end plates has a cylindrical portion extending integrally from the end surface,   A cylindrical portion configured to threadably engage a screw on the replacement object; With two screws,   Outside the space created by removing the damaged vertebrae, Elongate sized to span and completely engage abutting complete vertebra A longitudinal member;   Means for connecting the vertebral replacement implant to the longitudinal member. Assembly. 24. 24. The assembly of claim 23, which secures adjacent complete vertebrae,   Said replacement object defining a number of threaded openings;   The connection means,     A clamp for clamping the longitudinal member;     A screw attached to the clamp, wherein the one of the plurality of threaded openings is And the clamp engages the longitudinal member when the clamp is engaged with the longitudinal member. Said screw having a length sufficient to engage said replacement object. Three-dimensional. 25. 25. The assembly of claim 24 for securing an adjacent complete vertebra.   The clamp comprises a plate defining a hole having a circular seat;   Wherein the screw comprises a round head configured to engage the circular seat; Assembly. 26. 23. The assembly of claim 22 for securing an adjacent complete vertebra.   Each of the end plates is a flange defining the end face, and Comprising the flange extending outwardly from   The connecting means is an arc integral with the flange and projecting from the cylindrical portion. An adjacent arm so that the arm can engage the longitudinal member. An assembly having a free end configured to extend beyond the entire vertebra. 27. 27. The assembly of claim 26 for securing adjacent complete vertebrae,   A second arm formed at the free end to receive the longitudinal member; One hole and a set screw hole formed at the free end so as to traverse the first hole. Define   The connection means has a set screw screwed into the set screw hole,   A tip wherein the set screw engages a longitudinal member extending through the first hole An assembly having: 28. In the space formed by the removed vertebrae between adjacent complete vertebrae To make an implant for vertebral replacement   A length that has both ends and is dimensioned to span a portion of the space between the complete vertebrae An alternative object having   That of the complete vertebra when the implant is interposed in the space A pair of end plates having end surfaces contacting each one, each of said end plates being Said pair of end plates having an engaging portion extending integrally from,   Engage the end plate with the replacement object at a variable position along the length of the replacement object Between the opposite ends of the replacement object and the engagement portions of each of the end plates. Vertebral replacement implant comprising: 29. 29. The vertebral replacement implant of claim 28, wherein the engaging means comprises a frontal implant. Meshes formed on the ends of the replacement object and on each of the end plate engaging portions A vertebral replacement implant, including an implant. 30. 29. The vertebral replacement implant of claim 28, wherein the replacement object is Means fixed to each of the end plates to prevent the engaging means from being disengaged. A vertebral replacement implant for preparation. 31. Intervening in the space formed by the removed vertebra between two complete vertebrae Vertebral replacement implants   A thin-walled cylinder defining a hollow interior, wherein the wall of the cylinder is Defining a plurality of holes having a total area at least equal to 25% of the outer surface area;   The cylindrical body has opposite ends having continuous threads formed at each of the opposite ends;   A pair of end plates, each of which has an implant interposed within said space. A flange that defines an end surface that contacts the respective one of the full vertebrae when retracted Formed by   Each of the end plates further comprises a cylindrical portion projecting integrally from the flange;   The cylindrical portion is engaged with the screws at both ends of the thin cylinder. Define continuous screws,   When each of the end plates is threadably engaged with the end plate, the meat A vertebral replacement implant defining a through hole communicating with the hollow interior of the thin cylindrical body; plant. 32. A vertebral replacement implant according to claim 31,   The cylindrical portion of each of the end plates has a length protruding from the end face;   A crimp cut formed by the cylindrical portion along a portion of the length of the cylindrical portion; Define the chip,   The cylindrical portion is deformed by the crimp notch, closing the notch, When the cylinder is threadably engaged with the cylindrical portion of the end plate, the periphery of the cylinder is Vertebral replacement implant wherein the outer circumference of the cylindrical portion in And 33. The vertebral replacement implant according to claim 2, wherein a part of the plurality of holes is provided. A vertebral replacement implant extending through the first screw of the replacement object. 34. A vertebral replacement implant according to claim 7, wherein the replacement object is hollow. Having a cylindrical wall defining the interior,   The cylindrical wall defines a plurality of through holes;   The hole communicates with the hollow interior of the replacement object to allow tissue into the replacement object. A vertebral replacement implant that promotes head growth. 35. 35. The vertebral replacement implant of claim 34, wherein a portion of the plurality of holes is provided. A vertebral replacement implant extending through the external thread of the replacement object.